portage learning ap1 module 3 study guide bones

What components make up the skeletal system?

The skeletal system includes bones, cartilages, ligaments, and other connective tissues.

What is the primary function of cartilage in the skeletal system?

Cartilage helps hold bones together and allows for movement at joints.

What are the main types of skeletal cartilage?

The three main types are hyaline cartilage, fibrocartilage, and elastic cartilage.

What is the structure of hyaline cartilage?

Hyaline cartilage is the most common type, found in the rib cage and nose, and has a smooth, glassy appearance.

What distinguishes fibrocartilage from other types of cartilage?

Fibrocartilage contains thick bundles of collagen fibers, making it tough; examples include menisci and intervertebral discs.

What is the function of elastic cartilage?

Elastic cartilage provides rigid support with elasticity, found in structures like the external ear.

What are the two methods of cartilage development?

Cartilage develops through interstitial growth and appositional growth.

How does interstitial growth occur?

Interstitial growth occurs as chondrocytes grow and divide within the matrix, enlarging the cartilage from the inside.

What is appositional growth?

Appositional growth involves adding new layers of cartilage on the surface as cells in the perichondrium divide.

What are the two main divisions of the human skeleton?

The axial skeleton and the appendicular skeleton.

What bones are included in the axial skeleton?

The axial skeleton includes the skull, vertebral column, sternum, laryngeal skeleton, and thoracic cage.

What is the primary function of the appendicular skeleton?

The appendicular skeleton is specialized for flexibility and increased range of motion.

What are the six basic types of bones?

Long bones, flat bones, sutural bones, short bones, irregular bones, and sesamoid bones.

What is the function of long bones?

Long bones support body weight and enable movement; examples include the humerus and femur.

What characterizes flat bones?

Flat bones are thin and parallel, protecting vital organs; examples include the sternum and ribs.

What are sutural bones?

Sutural bones are small and flat, found between the flat bones of the skull, with numbers varying by individual.

What are short bones, and where are they found?

Short bones are small and cube-shaped, found in the carpals of the hand and tarsals of the foot.

What defines irregular bones?

Irregular bones have varied structures and shapes, such as the vertebrae and pelvic bones.

What is the role of sesamoid bones?

Sesamoid bones, like the patella, develop inside tendons to reinforce them and provide strength.

What is osseous tissue?

Osseous tissue is a hard, dense connective tissue that forms most of the adult skeleton.

What are the critical functions of the skeletal system?

The skeletal system supports the body, facilitates movement, protects organs, produces blood cells, and stores/releases minerals and fat.

How do bones facilitate movement?

Bones serve as points of attachment for muscles and act as levers, with joints functioning as fulcrums.

What minerals are primarily stored in bone tissue?

Calcium and phosphorus are the main minerals stored in bone tissue.

What is the difference between yellow and red bone marrow?

Yellow marrow stores fat and serves as an energy source, while red marrow is responsible for blood cell production.

What is hematopoiesis?

Hematopoiesis is the production of blood cells, occurring primarily in red bone marrow.

What happens to red bone marrow as a person ages?

As a person ages, red bone marrow is gradually converted to yellow bone marrow in long bones.

What type of bone marrow do newborns have?

All red bone marrow, which converts to yellow bone marrow over time in long bones.

What is the medullary cavity or marrow cavity?

A cavity filled with bone marrow that extends throughout the diaphysis of a long bone.

What is the difference between the epiphysis and diaphysis of a long bone?

The epiphysis is the widened end of the bone made mostly of spongy bone, while the diaphysis is the shaft or center length of the bone.

What is the function of articular cartilage?

It reduces friction when a bone articulates with another bone at a joint.

How is the structure of a flat bone different from that of a long bone?

Flat bones have a parallel structure with spongy bone between two layers of compact bone, while long bones have a medullary cavity and distinct epiphysis and diaphysis.

What are osteons?

Structural units of compact bone containing osteocytes in lacunae, surrounded by a matrix.

What is the role of canaliculi in bone tissue?

They are small channels that allow osteocytes to receive nutrients, remove wastes, and communicate with each other.

What is the periosteum?

A protective membrane covering the outer layer of compact bone, with a fibrous outer layer and an inner cellular layer.

What are osteoclasts?

Bone-absorbing cells that break down bone tissue and release calcium into the blood.

What is the function of osteoblasts?

They are immature bone cells that form new bone matrix and repair bone damage.

What are osteocytes?

Mature bone cells that maintain the mineral concentration of the bone matrix.

What are osteogenic cells?

Undifferentiated bone cells with high mitotic activity that can develop into osteoblasts. only bone cells that divide

What is ossification?

The process of converting tissue to bone.

What is calcification?

The process of depositing calcium salts into the matrix, occurring during ossification and in other tissues.

What is endochondral ossification?

The process where long bones develop by replacing hyaline cartilage models with bone.

What is intramembranous ossification?

The process of bone formation directly from mesenchymal tissue, typically forming flat bones.

What is trabeculae?

An open network of bony bars and plates in spongy bone, lacking osteons.

What is the composition of hydroxyapatite?

A mineral complex formed from calcium phosphate and calcium carbonate that gives bones their hardness.

What are Sharpey's fibers?

Collagen fibers that connect the periosteum to the bone.

What is the endosteum?

A membrane lining the marrow cavity and all internal cavities inside the bone.

How does spongy bone differ from compact bone?

Spongy bone lacks osteons and has a trabecular structure, while compact bone is dense and contains osteons.

What is the role of blood vessels in bone tissue?

They supply nutrients and remove wastes, allowing the bone to renew itself.

What happens to chondrocytes during endochondral ossification?

They grow, die, and disintegrate as the matrix calcifies, leading to the formation of bone.

What is the significance of the periosteum in bone health?

It provides a structure for blood vessels and protects the bone from surrounding structures.

What is the function of the lacunae in bone tissue?

They house osteocytes and are surrounded by the bone matrix.

What initiates the formation of the medullary cavity in long bones?

Blood vessels invade the shaft, enlarging cavities and bringing osteogenic cells, which become osteoblasts.

What is the role of chondrocytes in bone growth?

Chondrocytes and cartilage grow at the ends of the bone, increasing its length while bone replaces cartilage in the diaphysis.

What are secondary ossification centers?

They are formed at each end of the bone as blood vessels penetrate the epiphyses, delivering osteoblasts to develop bone.

What is the epiphyseal plate?

It is the growth plate formed between the diaphysis and epiphysis, where cartilage continues to grow and divide.

What happens to epiphyseal cartilage at puberty?

The production of epiphyseal cartilage slows, while osteoblast activity increases, leading to the eventual disappearance of cartilage.

What is the epiphyseal line?

It is the remnant of epiphyseal cartilage in mature adult bones after growth is complete.

What types of bones are formed through intramembranous ossification?

The flat bones of the face, most cranial bones, and the clavicles.

What is the role of osteoblasts during bone formation?

Osteoblasts secrete osteoid, which calcifies and forms bone tissue.

How do osteocytes form from osteoblasts?

Once entrapped in the calcified matrix, osteoblasts transform into osteocytes.

What is the purpose of the nutrient artery and vein?

They supply blood to the diaphysis during endochondral ossification.

How do periosteal vessels contribute to bone development?

They supply blood to the osteons in the outer layer of the shaft and enter the epiphyses during embryonic development.

What is the significance of remodeling in bone tissue?

It allows for the repair of damaged bone and the replacement of old bone with new bone.

What is appositional bone growth?

It is the growth of bone in diameter, which can continue even after longitudinal growth ceases.

What factors influence bone thickness?

Physical use, hormonal balance, and mechanical stress affect bone thickness and remodeling.

How does exercise affect bone density?

Regular exercise increases bone density, with resistance training being particularly effective.

What dietary components are essential for bone growth?

Calcium, phosphate, Vitamin C, Vitamin A, Vitamin K, B12, and Vitamin D are necessary for proper bone development.

What role does the endocrine system play in bone health?

It produces hormones that control bone growth, maintenance, and remodeling.

What is the function of growth hormone (GH) in bone development?

GH controls bone growth in several ways, influencing osteoblast activity and bone matrix maintenance. mkaes bones longer via chondrocytes proliferation and denser via calcium retention.

What hormone does the pituitary gland secrete to control bone growth?

Growth hormone (GH)

How does growth hormone (GH) affect long bones?

It triggers chondrocyte proliferation in epiphyseal plates, increasing their length.

What role does thyroxine play in bone growth?

It promotes osteoblastic activity and the synthesis of bone matrix. makes osteoblasts grow faster

What hormones are responsible for the adolescent growth spurt?

Estrogen in females and testosterone in males.

What is the function of calcitriol in bone health?

It stimulates the absorption of calcium and phosphate from the digestive tract.

What is the role of parathyroid hormone (PTH) in calcium balance?

It stimulates osteoclast proliferation and activity, promoting bone resorption and calcium release into the blood. it triggers kidneys to consume more calcium then

What effect does calcitonin have on blood calcium levels?

It inhibits osteoclast activity and stimulates calcium uptake by bones, reducing blood calcium concentration.

What is a fracture?

A broken bone.

What is a closed reduction in fracture treatment?

Manipulating and setting a broken bone into its natural position without surgery.

What is an open reduction in fracture treatment?

Surgical exposure of the fracture to reset the bone.

What is a displaced fracture?

A fracture that produces abnormal bone alignment.

What is a nondisplaced fracture?

A fracture that maintains normal bone alignment.

What characterizes a transverse fracture?

It occurs straight across the long axis of the bone.

What happens in a spiral fracture?

Bone segments are pulled apart due to a twisting motion.

What is a comminuted fracture?

A fracture with several breaks resulting in many small pieces between two large segments.

What is an impacted fracture?

One fragment is driven into another, usually due to compression.

What is a greenstick fracture?

A partial fracture where only one side of the bone is broken.

What is a compression fracture?

A fracture where the bone is crushed, common in osteoporotic bones.

What is a depressed fracture?

A fracture where the broken bone is pressed inward, common in skull fractures.

What is an open (or compound) fracture?

A fracture where at least one end of the broken bone tears through the skin.

What is a closed (or simple) fracture?

A fracture where the skin remains intact.

What is the first step in bone fracture repair?

Formation of a fracture hematoma due to blood clotting.

What forms within 48 hours after a fracture?

A fibrocartilage callus.

What is the role of osteoclasts in fracture healing?

They resorb dead bone during the healing process.

What is osteopenia?

A normal aging process where osteoblast activity slows but osteoclast activity remains the same.

What is osteoporosis?

A disease characterized by a significant decrease in bone mass, compromising bone function.

What histological changes characterize osteoporosis?

Reduction in the thickness of compact bone and the number and size of trabeculae in spongy bone.

At what age do females typically start losing bone mass more quickly?

Around 50 years of age, coinciding with menopause.

Why is osteoporosis more common in females than males?

Females experience a significant decline in estrogen levels during menopause, which is crucial for bone health.

What is the best prevention strategy for osteoporosis?

A childhood diet rich in calcium and vitamin D, along with weight-bearing exercises.

What is Paget's disease?

A bone disorder characterized by overactive osteoclasts leading to abnormal bone remodeling.